On 2022-06-29 00:48, Christoph Hellwig wrote: > On Wed, Jun 15, 2022 at 10:12:32AM -0600, Logan Gunthorpe wrote: >> A pseudo mount is used to allocate an inode for each PCI device. The >> inode's address_space is used in the file doing the mmap so that all >> VMAs are collected and can be unmapped if the PCI device is unbound. >> After unmapping, the VMAs are iterated through and their pages are >> put so the device can continue to be unbound. An active flag is used >> to signal to VMAs not to allocate any further P2P memory once the >> removal process starts. The flag is synchronized with concurrent >> access with an RCU lock. > > Can't we come up with a way of doing this without all the pseudo-fs > garbagage? I really hate all the overhead for that in the next > nvme patch as well. I assume you still want to be able to unmap the VMAs on unbind and not just hang? I'll see if I can come up with something to do the a similar thing using vm_private data or some such. I was not a fan of the extra code for this either, but I was given to understand that it was the standard way to collect and cleanup VMAs. Thanks for the reviews, Logan
